Safety device for projectiles



Jan. 22, 1957 E. w. BRANDT SAFETY DEVICE FOR PRoJEcT'ILEs Filed April 22, 1952 ATTORNEY:

United States Patient O SAFETY DEVICE Fon rRoJEC'rILEs Edgar William Brandt, Geneva, Switzerland, assignor to Anstalt fur die Entwicklung von Erfindungen und Gewerblichen Anwendungen Energaj Vaduz, Liechtenstein, a corporation of Liechtenstein l Application April 22, 1952, Serial No. 253,618@

1 Claim. (Cl. 1112-73) This invention relates to projectiles of the type comprising a head fuze and a detonator disposed towardsl kind comprising two parts which are movable relatively to loneanother, one ofwhich parts has `at* least one groovein which is engaged a sliding memberintegral with the other part, forming an obturator, and which is operated by a resiliently constrained member, for

example, a spring. The moving part of the device serves as a screen in the safety position, and must be dislodged passage for the transmission of fire from the head fuze to the detonator.

The safety device according to the present invention is characterised in that the resiliently constrainedthrust member is secured by itsfront end to the obturator and is provided: at its rear end with a valve which, under the v action of the thrust member, keeps the internal passage of the safety device closed until the principal obturator is completely released.

The result produced by the aforedescribed arrangement is that until the end of the operation of the safety mechanism, the valve ensures perfect obturation, and

that, in the event of accidental percussion of the head'` fuze immediately after firing the shot, the muzzle safety device still functions by virtue of the fact that the valve hereinbefore referred to is forced under the action of the gases liable to pass between the two parts of the device, tightly against its seat.

According to one embodiment of the invention, in order to supplement the action of the safety device, the obturatoi has on its outer face a group of sealing grooves which, similarly to piston rings, oppose the passage of the gases between the two parts of the device, as long as the latter has not operated.

In order to enable the invention to be more readily understood, reference `is made to the accompanying drawings, Which" illustrate diagrammatically and by way of example, one embodiment thereof and in which:

Fig. 1 illustrates the projectile in partial axial section;

Fig. 2 is an enlarged axial section of the safety device denoted by the reference numeral 1 in Fig. 1; and

after the shot has been fred,`thereby freeing the useful Fig. 3 shows the functioning of the safety device shown in Fig. 2. Y

As shown in Fig. 1, the safety device 1 of the present invention is interposed, in a hollow-charge kgrenade 2, between a head fuze 3 and a detonator 4, the latter havice ing the function of communicating the fire to a relay charge 5, which explodes the high explosive charge 6, the metal cap 7 of which lines the cavity 8.

Figures 2 and 3 show details ofthe construction of the safety device having, in a casing 1a a hollow inertia device or obturator 9, which carries two slides 10 each of which engages in a zig-zag groove 11 provided in the support 12.

An ejection spring 13 holds the inertia member 9 bearing against the slide 10 at the bottom of the blind part 11b of the groove 11 (Figure 3). In this position, the obturator 9 prevents transmission of fire from the primer 14 to the detonator 4.

The spring 13 is secured at its yfront end to a nipple 15 firmly fitted in the solid head of the obturator 9, and a small seal 16 is fixed to the rear end of the spring 13, s0 that in the safety position, the seal 16 bears against a circular seating 17 formed in the base of the support 12 and thus reinforces the obturation provided by the inertia member 9.

In'order to ensure perfect tightness of the safety device, the inertia member 9 is provided on its outer face with a series of grooves 18 which imposes a baied path on any accidental transmission of fire.

On firing the shot, the inertia member 9 under the influence' of the propulsive action, while following the movement imposed on it by the blind part 11b of the groove, compresses the thrust member or spring 13 by inertia and then, on the cessation of the positive acceleration, the spring 13 pushes the inertia member 9 towards the front and its slides `10 follow respectively the branches .11a ofeach of the zig-zag grooves. As long as the spring 13 has not been completely slackened, the seal 16 remains in position and continues to close the passage provided in the base of the support 12. The inertia member or obturator 9, when ejected by the spring 13, frees the `firing orifice and by falling into the cavity 8 of the projectile, takes up position, together with the attached spring 13 and seal 16, near the primer 14, at 9a (Figure l). Since the spring 13 is secured to the obturator 9, it accompanies the latter whenit is displaced from the cap 8, so that lwhen the explosion occurs the spring is no longer in the field of action of the perforating jet. Experience shows that `the penetrating power of the hollow explosive charge is thereby improved.

It is obvious that the invention has only been described by way of example and that various modifications and alterations can be made thereto without departing from the scope thereof as defined by the appended claim.V

What I claim is:

A safety and delay device for a projectile fuse, comprising a support with a longitudinally extending passage References Cited in the file of this patent UNITED STATES PATENTS Prato oct. 1o, 1944 Brandt May 6, 1952 FOREIGN VPATENTS Switzerland 1 Aug. 1, 1950 

